There have been some reports of the macOS versions of some XCVG Systems projects not working properly. These builds are generally provided as-is on a semi-experimental basis, as I have a very limited ability to test them. However, it seems the issues generally fall into one of a few categories.
Binary is not marked as executable
The app may completely fail to run. This is caused by the application binary inside the .app package not being marked as executable. This likely occurs because all building and packaging is done on a Windows system.
The easy way to work around this is to use a third-party unarchiving tool that silently fixes permissions when extracting from the distributed zip file. I’ve found that The Unarchiver does so. Alternatively, you can manually add the executable attribute to the binary (a file in *.app/Contents/MacOS) using chmod from the Terminal.
This issue is known to affect the macOS builds of games from early 2020, including but not limited to Bang Ouch, Toilet Paper Panic, and Heavy Metal Slug. Older games are likely affected as well.
Future builds will fix this problem, or at least attempt to.
Non-Store apps are not allowed
Depending on your system security settings, macOS may block all apps not downloaded from the App Store.
This behaviour is user-configurable and can be disabled from System Preferences->Security And Privacy. It is on the General tab, near the bottom.
For more information, refer to the Apple support article.
There are currently no plans to distribute any projects through the App Store.
App is not signed or notarized
The app may be recognized as an app, but macOS may refuse to run it. This is because the app is not notarized. At the time of writing, macOS 10.15 Catalina requires this by default.
It is possible to bypass this, but it is slightly obtuse. Right-click or control-click on the app and select Open from the context menu. A slightly different dialog will pop up, asking you if you want to run anyway. Once you allow it, it will run and you will not be prompted in the future.
For more information, refer to the Apple support article.
There are currently no plans to provide signed or notarized builds in the future.